I'm going to go against the grain of the majority here, which has so far been the socially middle class (of which the financial and economic expectations are closer to the lower upper class if not higher) offering socially middle class solutions (and knowing that those are financially impractical for most governments).
The counterpoint is that poor people are having more kids than the middle class, especially those of the socially middle class. Thus governments can create the conditions for additional population growth more cheaply by creating the conditions for a larger lower/working class. This can be easily achieved through reigning in consumerism (i.e. kneecaping domestic advertising, the economic shortfall made up through maintaining strong export sector) and limiting higher education (but maintaining strong technical education), thus creating skill workers with relatively low social expectations.
Some additional policies that can be done it maintaining 3rd spaces, small close knit communities, and multigenerational households in order to offload the majority of the childrearing costs to the people themselves in nonmonetary ways.